import hash from "hash.js";
const codeMessage = {
  200: "服务器成功返回请求的数据。",
  201: "新建或修改数据成功。",
  202: "一个请求已经进入后台排队（异步任务）。",
  204: "删除数据成功。",
  400: "发出的请求有错误，服务器没有进行新建或修改数据的操作。",
  401: "用户没有权限（令牌、用户名、密码错误）。",
  403: "用户得到授权，但是访问是被禁止的。",
  404: "发出的请求针对的是不存在的记录，服务器没有进行操作。",
  406: "请求的格式不可得。",
  410: "请求的资源被永久删除，且不会再得到的。",
  422: "当创建一个对象时，发生一个验证错误。",
  500: "服务器发生错误，请检查服务器。",
  502: "网关错误。",
  503: "服务不可用，服务器暂时过载或维护。",
  504: "网关超时。"
};

const checkStatus = response => {
  if (response.status >= 200 && response.status < 300) {
    return response;
  }
  const errortext = codeMessage[response.status] || response.statusText;
  // notification.error({
  //   message: `请求错误 ${response.status}`,
  //   description: errortext
  // });
  const error = new Error(errortext) as any;
  error.name = response.status;
  error.response = response;
  throw error;
};

const cachedSave = (response, hashcode) => {
  const contentType = response.headers.get("Content-Type");
  if (contentType && contentType.match(/application\/json/i)) {
    response
      .clone()
      .text()
      .then(content => {
        sessionStorage.setItem(hashcode, content);
        sessionStorage.setItem(`${hashcode}:timestamp`, Date.now() as any);
      });
  }
  return response;
};
export default function request(url, option) {
  // dispatch({
  //   type: "layout/loading_show"
  // });
  const options = {
    expirys: false,
    ...option
  };
  const fingerprint = url + (options.body ? JSON.stringify(options.body) : "");
  const hashcode = hash
    .sha256()
    .update(fingerprint)
    .digest("hex");

  const defaultOptions = {
    credentials: "include"
  };
  const newOptions = { ...defaultOptions, ...options };
  if (
    newOptions.method === "POST" ||
    newOptions.method === "PUT" ||
    newOptions.method === "DELETE"
  ) {
    if (!(newOptions.body instanceof FormData)) {
      newOptions.headers = {
        Accept: "application/json",
        "Content-Type": "application/json; charset=utf-8",
        ...newOptions.headers
      };
      newOptions.body = JSON.stringify(newOptions.body);
    } else {
      // newOptions.body is FormData
      newOptions.headers = {
        Accept: "application/json",
        ...newOptions.headers
      };
    }
  }

  const expirys = options.expirys && 60;
  // options.expirys !== false, return the cache,
  if (options.expirys !== false) {
    const cached = sessionStorage.getItem(hashcode);
    const whenCached = sessionStorage.getItem(`${hashcode}:timestamp`) as any;
    if (cached !== null && whenCached !== null) {
      const age = (Date.now() - whenCached) / 1000;
      if (age < expirys) {
        const response = new Response(new Blob([cached]));
        return response.json();
      }
      sessionStorage.removeItem(hashcode);
      sessionStorage.removeItem(`${hashcode}:timestamp`);
    }
  }
  // @ts-ignore
  return fetch(url, newOptions)
    .then(checkStatus)
    .then(response => cachedSave(response, hashcode))
    .then(response => {
      if (newOptions.method === "DELETE" || response.status === 204) {
        return response.text();
      }
      return response.json();
    })
    .catch(() => {})
    .finally(() => {});
}
